The posts of the thread about technologies to keep the water of the recently detected martian sea provides a welcome opportunity to have a friendly home at Mars.

If the colonists would have their habitats beneath the surface of that sea and if it could be managed to keep that surface icy but have a large liquid water in the depth then this would allow for having fishes and sea plants within the direct and immediate surroundings of the habitats.

It would be sufficient to have a look at the ground of seas and ponds of similar depth on Earth to knwo what to carry into that sea.

There could be locations in the depth where there are submarine ponds with the atmosphere of the habitats and its pressur above it.

What technologies and possibilties could you imagine now under such circumstances?

desertbadger - this came to me because of your change from "Nice Administrator" to "subterranean" - what would you feel and think if you were living in such asurroundings?

The biggest problem I see is that people don't like burrowing. They like to be able to see the sky and the terrain around them, not a bunch of tunnels and walls. I still prefer the inflatable habitat, as per Kim Stanley Robinson's Red Mars.

As I see it a colony at the martian surface will be more fragile than a submarine colony in or under that sea. Your arguments are right - they would be a reason too to design the submarine surroundings like suggested in my post.

Submarine the colony will be protected much more against radiation, solar wind or meteorites. And it will be easier to keep the internal atmosphere of the colony.

This all might apply to a simple permanent manned Mars station too.

Perhaps there will be special sites where the people can look to the sky by spectatoring or telescoping windows?

Perhaps there will be special sites where the people can look to the sky by spectatoring or telescoping windows?

You could use a periscope arrangement or even LCD panels connected to TV cameras to give outside views, afterall its not like you can open a window is it? Some modern basement homes use a solar collector to channel sunlight where it is needed, perhaps something like this could be used.

_________________A journey of a thousand miles begins with a single step.

In between - and revoked by Sigurd's April joke - I remember that beneath the surface of ice there may be liquid water. This is - or has been - assumed to be valid at the jovian moon Europa. So there is sufficient reason to suppose it to be valid at Mars too. Arguments against it may be that the sea isn't that deep compared to the assumptions and estimations about Europa's oceans and that the sea seems to be very very old and unchanged whereas the icy surface of Europa seems to break repeatedly within very short times (weeks, months, years).

But using a thermonuclear power source it may be easy to provide liquid water at the ground of that sea and keep it liquid easyly.

I think that liquid water under the frozen sea on Mars is unlikely unless there is some form of termal energy melting it. At the moment no one has seen any current volcanic action there so this tends to rule geothermal sources of heat out, although there appears to be some evidence that Mars might not be dormant the jury is still out.

This cant really be compared to the ice on Europa because Europa's core is probably kept moltan due to the massive gravitational stresses exerted by Jupiter.

I wonder whether it would be possible to channel enough solar energy using reflectors, like a magnifying glass, below the surface on Mars to melt the ice rather than use a nuclear power source.

If a subterrainian cavern was opened up as a Mars habitat, would the ice contain the atmosphere or would an air tight membrane be required to seal it?

_________________A journey of a thousand miles begins with a single step.

Perhaps there would be a combination of several technologies - the membrane plus an air lock, a temperature lock and a special zone where temperature is reduced to a level below general martian temperature.

I would prefer temperature generating technologies like a nuclear generator but not think of using reflectors or magnifying glasses to melt ice - the nuclear generator seems to be less complex and less expensive than a system that directs sunlight into the deep or into a cavern. Unless directing could be done as a by-effect of a system that provides significant major use of other kinds. Are such uses or purposes of light directing systems imaginable?

A bundle of fibre optic cables in a protective sheaf (I'm thinking of something like a medical endoscope) could be used to transfer the solar heat to a subterrainian cavern fairly easily, quite a lot of energy could be transfered in this way and it could be directed to whereever it was required. The bundle could also be used as a boring tool to melt through the ice until it reached the required depth.

A large body of underground water would act like a thermal heat store and keep the temperature above the ambient even when the energy source was removed for a time.

Some fibre obtics are specifically designed to work in the infra red portion of the spectrum, by mixing different types of fibre optic light and heat could be separated. Using light from the surface would help colonists synchronise with the Martian Day.

_________________A journey of a thousand miles begins with a single step.

Agreed - and your last issue would be a good statement in the thread about time and clocks too.

A few moments ago I had another idea how to provide energy in the cavern benath the ice: Reflectors and magnifying glasses could be used to heat water in a container at the surface too. If sufficient heating would be provided that way to get steam then that steam could be directed into the cavern - providing the required temperature to melt ice.

Would electricity suffiently efficient to generate the required temperature permanently?

Dipl.-Volkswirt (bdvb) Augustin (Political Economist)

EDIT: Because of the nature and toe properties of steam it seems to be a nonsense-idea to provided in a container at the surface and then direct it into a submarine or subterranean cave - but could it be done by a pump, by pressure or by delivering it enclosed in a container? But the heating could take place in the depth if the reflectors and the magnifying glasses could provide sufficient sunlight to provide the temperature required for steam there. I have been speaking of a container - that container might provide eartian pressure to make sure that water has to be at 100° C to convert into steam.

Such a station beneath the surface of that frozen sea - or the equipment for it at least - could be tested in a glacier. A glacier is accessable by its slits and it contains holes.

That a good idea, I wonder whether the Mars society would be interested in setting something up? Someone would have to design a heating element first, although it could be run from an ordinary generator.

Rather than use a glacier what about on the summit of a mountain where air pressure would be lower and conditions more extreme. Or if that was not a good idea due to creating possible avalanche, you could use Siberia or somewhere similar where permanent frozen ground exists. The mixture of soil and ice might be a good analogue for Mars.

If the boring tool was self contained it could be dropped from a plane to simulate a Mars landing. This technology could have a spin off for creating survival habitats in areas hit by natural disasters

_________________A journey of a thousand miles begins with a single step.

I had the idea to use a glacier because the initial idea of this thread is a habitat within ice - within the ice of the martian frozen sea. A glacier would allow to test technologies which make such a within-the-ice-habitat possible without melting the surrounding ice - it could be tested too which ways it can be made possible too to have a pond or a pool available within the habitat - a pond of water won by melting ice.

I have forgotten one important place where test could be done and where the technolgy may provide practical use for common people: Iceland...

But tests on mountain tops would complete the tests in a glacier because they would take into account lower atmospheric pressure - but such test could be done too at JP Aerospace's Dark Sky Stations and floating ports...

I am thinking about proposing the tests to the Mars Society at their german homepage. They are already testing ideas and technologies by their project FMARS at the Haughton Crater in the canadian Arctis - may be they are close enough to usable glaciers and their slits there and may be too they are interested.

The vapor pressure of water at 0 degrees C is about 6 millibars which is less than the pressure of the martian atmosphere (up to 9 millibars depending on altitude.) You wouldn't need a cap of ice to keep the water from boiling away. You would just need to cover it with something like saran wrap to keep it from evaporating, but the saran wrap wouldn't have to hold in any pressure, and if it were punctured there would just be slow evaporative loss of water and nothing more.

Several meters below the surface of the water the pressure would be 1 bar (or whatever pressure you want for your hab) so you can have a thin plexiglass dome that doesn't have to hold in any pressure either. The weight of the water holds down the air and the pressure of the air holds up the water. You could have a large open area perhaps in the bottom of a crater covered by plexiglass, liquid water, and saran wrap. You could look up and see the sky.

You would need to continually heat the water to keep it from freezing, but it would provide nice shielding from cold, radiation, and meteorites as mentioned before. And it would make a great cold sink for a nuclear or solar powered heat engine.